spi/s3c64xx: Don't free controller_data on non-dt platforms

When s3c64xx-spi is instantiated from device tree an instance of
struct s3c64xx_spi_csinfo is dynamically allocated in the driver.
For non-dt platform it is passed from board code through
spi_register_board_info(). On error path in s3c64xx_spi_setup()
function there is an attempt to free this data struct
s3c64xx_spi_csinfo object as it would have been allocated in the
driver for both, dt and non-dt based platforms. This leads to
following bug when gpio request fails:

spi spi1.0: Failed to get /CS gpio [21]: -16
kernel BUG at mm/slub.c:3478!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0    Not tainted  (3.6.0-rc5-00092-g9b0b493-dirty #6111)
PC is at kfree+0x148/0x158
LR is at s3c64xx_spi_setup+0xac/0x290
pc : [<c00a513c>]    lr : [<c0227014>]    psr: 40000013
sp : ee043e10  ip : c032883c  fp : c0481f7c
r10: ee0abd80  r9 : 00000063  r8 : 00000000
r7 : ee129e78  r6 : ee104a00  r5 : fffffff0  r4 : c047bc64
r3 : 40000400  r2 : c047bc64  r1 : c04def60  r0 : 0004047b
Flags: nZcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: 10c5387d  Table: 4000404a  DAC: 00000015
Process swapper/0 (pid: 1, stack limit = 0xee0422f0)
Stack: (0xee043e10 to 0xee044000)
...
[<c00a513c>] (kfree+0x148/0x158) from [<c0227014>] (s3c64xx_spi_setup+0xac/0x290)
[<c0227014>] (s3c64xx_spi_setup+0xac/0x290) from [<c02251a4>] (spi_setup+0x34/0x4c)
[<c02251a4>] (spi_setup+0x34/0x4c) from [<c02258d0>] (spi_add_device+0x98/0x128)
[<c02258d0>] (spi_add_device+0x98/0x128) from [<c02259d4>] (spi_new_device+0x74/0xa8)
[<c02259d4>] (spi_new_device+0x74/0xa8) from [<c0225a2c>] (spi_match_master_to_boardinfo+0x24/0x44)
[<c0225a2c>] (spi_match_master_to_boardinfo+0x24/0x44) from [<c0225b40>] (spi_register_master+0xf4/0x2a8)
[<c0225b40>] (spi_register_master+0xf4/0x2a8) from [<c043fe0c>] (s3c64xx_spi_probe+0x34c/0x42c)
[<c043fe0c>] (s3c64xx_spi_probe+0x34c/0x42c) from [<c01fc198>] (platform_drv_probe+0x18/0x1c)

There should be no attempt to kfree controller_data when it was
externally provided through the board code. Fix this by freeing
controller_data only when dev->of_node is not null.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>